a. Technical Field
The present invention relates to hearing devices, and, more particularly, to miniature hearing devices for inconspicuous wear.
b. Description of the Prior Art
(1) The Challenges of Miniature Canal Devices
The benefits of miniature hearing device for placing deep in the ear canal are many. They include improved high frequency response, less distortion, reduction of feedback and improved telephone use (Chasin, M. CIC [Completely In the Canal] Handbook, Singular Publishing, pp 10-11, 1997, referred to hereinafter as xe2x80x9cChasinxe2x80x9d). A major benefit for xe2x80x9can invisible hearing devicexe2x80x9d for the user is cosmetic in nature since hearing aid use is often associated with aging and disability. Hearing devices that fit deep in the ear canal are typically one of two types: (1) In-The-canal (ITC) type which fits largely in the concha cavity (3 in FIG. 4 hereof) and extends into the ear canal 1, or; (2) Completely-In-the-Canal (CIC) type which fits completely within the ear canal 1 past the aperture 2 as shown in FIG. 5 hereof.
A conventional hearing device includes a battery, a microphone, an amplifier, and a receiver (speaker), among other components, all of which are housed within an outer shell composed of acrylic or plastic material. A movable battery enclosure, in the form of a door, lid or a compartment, is typically provided to enclose the battery of the device within and to facilitate its removal when depleted. Removal is typically performed by opening the enclosure and manually grasping the battery with fingers (for example see 24 in FIGS. 1 and 2 in U.S. Pat. No. 4,272,591 to Brander). Since battery enclosures are generally permanent structures within a conventional hearing device, they must be made durably thick to last for the life expectancy of the hearing device. For example, the wall thickness of battery doors is typically greater than 0.5 millimeter (mm). Various physical features of battery enclosures (i.e., hinge, hinge-receptacle, locking features, door-knobs, etc.) occupy valuable space within a hearing device. These and other space inefficiencies associated with battery enclosures of conventional hearing devices add significant challenges in the fabrication and fit of miniature hearing devices.
With continued improvements in miniaturization of hearing aid components, the battery has emerged as the largest single component in canal hearing devices (ITC and CIC devices are collectively referred to herein as canal devices). Resorting to smaller batteries to reduce the overall size of the device is not practical for most users who expect a prolonged use of their batteries prior to depletion and replacement. Eliminating space-inefficiencies of battery enclosures will have a significant impact on reducing the overall size and improving the fit of miniature hearing devices.
Another problem associated with battery enclosures of conventional devices is related to the placement and removal of the battery. The tiny size of a door and hearing aid battery present a serious dexterity challenge to many hearing aid users who are elderly and may suffer from hand-tremors, arthritis, poor vision and other ailments that limit their ability to manipulate small structures.
(2) State of the art in Battery Enclosure in Hearing Devices
As mentioned above, prior art hearing devices typically comprise a movable battery enclosure contained within a shell at the lateral (face-plate) side of the hearing device. For example, U.S. Pat. No. 5,201,008 to Arndt et al. (xe2x80x9cArndtxe2x80x9d) describes an open-topped battery compartment (24 in FIG. 1 of Arndt) and subsequently covered by a lid (16 in FIG. 1 of Arndt). The space inefficiencies associated with the movable battery compartment and lid prohibit the fabrication of highly miniature canal device for deep fitting in the ear canal.
U.S. Pat. No. 4,153,758 to Cerny (xe2x80x9cCernyxe2x80x9d) describes a miniature holder and carrier of a battery for positioning it into the door of a hearing device. Although Cerny""s proposal may facilitate insertion and removal of the battery into and from the hearing device, no space efficiencies are realized by the proposal since a battery door is still required for proper operation as disclosed.
U.S. Pat. No. 4,931,369 to Hardt et al. (xe2x80x9cHardtxe2x80x9d) describes a battery enclosure or chamber formed by the housing and movable cover. Thus, a separate battery compartment is eliminated for improved space efficiency. However, since the formed chamber completely surrounds the battery placed within, the thickness of the enclosure also occupies valuable space. Furthermore, Hardt""s arrangement requires considerable manual dexterity from the user to manipulate the miniature cover and to position or remove the battery within it.
U.S. Pat. No. 5,784,470 to Fackler et al. (xe2x80x9cFacklerxe2x80x9d) describes a space efficient hinged battery door and faceplate arrangement for a CIC device. The battery enclosure partially protrudes from the face-plate (FIG. 3 of Fackler) thus allowing the battery to occupy less space within the shell and effectively reducing the volume of the shell for deeper positioning within the ear canal. However, the miniature door also presents a challenge for those with limited dexterity as mentioned above.
U.S. Pat. No. 5,117,997 to Voroba (xe2x80x9cVorobaxe2x80x9d) describes a battery dispenser apparatus, which aids in the dispensing and removal of hearing aid batteries. The apparatus is clearly designed for conventional hearing aids (30 in FIG. 1 of Voroba) which comprise a hinged battery door/compartment (32) for opening and placing the battery within. Similarly, a miniature door/compartment for canal devices presents a serious challenge for those with limited manual dexterity.
It is a principal objective of the present invention to provide a highly space efficient canal hearing device for positioning deep in the ear canal.
Another objective of the invention is to provide a battery assembly which is highly accessible, and thus easily inserted and removed without requiring a door or a movable battery compartment.
Yet another objective is to provide a battery dispenser which is adapted to enable easy and direct transfer of a battery therefrom into operative engagement with the hearing device, thus eliminating a need for handling and manipulation of the battery itself by the user.
The present invention provides a space efficient battery assembly and convenient replacement method for miniature hearing devices. The battery assembly is partially inserted into a receptacle cavity within a hearing device. The battery assembly has a protruding segment, which remains outside the battery cavity and is directly exposed to the environment of the ear outside the hearing device. The battery assembly comprises a thin-walled covering affixed or molded to its protruding segment, thus disposable along with the battery. The insertable segment of the battery assembly provides electrical and mechanical connectivity with the receptacle cavity of the hearing device. The partial insertion of the battery assembly conserves valuable space within the housing of the hearing device of the present invention, thus allowing for deeper insertion into the ear canal. Further reduction in the size of the hearing device is achieved by eliminating a movable door or battery compartment typically employed in conventional hearing aid designs. Such a battery assembly is highly accessible and thus easy to place and remove. This is particularly useful for the elderly who may have limited manual dexterity or poor eyesight.
In a preferred embodiment of the invention, a battery dispenser holding several battery assemblies is provided. The battery dispenser facilitates the placement of a battery assembly by directly transferring a battery assembly from the dispenser to the hearing device, without resorting to any direct manual manipulation of the battery assembly. This is accomplished by first holding the hearing device and introducing its receptacle cavity onto the insertable segment of a battery assembly exposed within the dispenser. Once the insertable segment of the battery assembly is fully inserted into the receptacle cavity of the hearing device, the retention force within the receptacle cavity causes the battery assembly to disengage from the dispenser as the hearing device is being removed away from the dispenser area. In the preferred embodiment, the battery dispenser is in the form of a disposable cartridge, which also comprises an extractor and a disposal reservoir for the removal and storage of depleted battery assemblies.